When offered a chance to clarify the comment, Spicer said Hitler "was not using the gas on his own people the same way Assad is doing."

Hitler did employ chemical weapons against the German people. Prior to Hitler's rise, Jewish people were assimilated German citizens. Nazi Germany also targeted the handicapped, homosexuals and Catholics — people considered citizens of Germany — during the Holocaust.

In a second clarification, Spicer said he was not "trying to lessen the horrendous nature of the Holocaust."

"However, I was trying to draw a contrast of the tactic of using airplanes to drop chemical weapons on innocent people," he said.

A few minutes later, Spicer released yet another clarification, saying he was not trying to "lessen the horrendous nature of the Holocaust."

From the print pool, what appears to be a 4th Hitler clarification from Spicer, which adds a sentence at the end not there previously pic.twitter.com/lxZDJb2rwt